Nano-metallic Cu and carbon material graphene nanoplatelets(GnPs) were chosen to modify organic phase change material(PCM) myristic acid(MA). The Cu/MA hybrid PCMs were prepared by adding the Cu at different mass fraction(1%

2%

3%

4%) into MA

and the GnPs/MA hybrid PCMs were produced by adding the GnPs at various mass fraction(1%

2%

3%) into MA. Thermal properties of the hybrid PCMs were determined by using differential scanning calorimetry(DSC) analysis and transient hot-wire method. Besides

the microscopic

chemical and crystalline structure of the hybrid PCMs were characterized by scanning electron microscope(SEM)

fourier transformed infrared(FT-IR) and X-ray diffraction(XRD). The results indicated that solid and liquid thermal conductivity of the Cu/MA hybrid PCMs increased linearly with the increase of Cu content. The solid thermal conductivity of 1%(mass) GnPs/MA hybrid PCM significantly raised by 101.51% compared to that of pure MA

and the thermal conductivity of hybrid PCMs kept increasing with the increase of GnPs mass fraction but increment extent slowed down. FT-IR spectra showed that the interactions between Cu and MA

and GnPs and MA were physical. DSC analysis demonstrated that both supercooling degree and phase change latent heat of MA reduced with the addition of Cu or GnPs. With the increase of mass fraction

the phase change latent heat of hybrid PCMs decreased gradually. The time of thermal energy release of 4%(mass) Cu/MA and 3%(mass) GnPs/MA hybrid PCMs decreased by 23.4% and 38.7% respectively compared to that of pure MA. After 4%(mass) Cu/MA and 3%(mass) GnPs/MA hybrid PCMs experiencing 300 accelerated thermal cycles

the crystalline structure and phase change temperature basically stayed unchanged

while phase change latent heat reduced to approximate 168 J·g-1 and 181 J·g-1 respectively

which still met the requirements of heat storage and release. Both materials had good thermal cycling reliability.